MINNEAPOLIS (WCCO) – The Centers for Disease Control estimate that nearly 3 of 5 public swimming pools are contaminated with fecal matter.

According to the CDC, the figures from their tests of polls conducted during last summer’s swim season showed about 58 percent of the samples tested positive for E. coli and bacteria typically found in human feces.

However, while fecal matter was present in the majority of samples, none of the water tested contained the specific E. coli strain that causes illness.

The CDC said their findings indicate swimmers are contaminating the water either through “fecal incidents” in the pool, or because they haven’t showered properly before entering the pool.

The study also showed 59 percent of pools testing positive for Pseudomonas aeruginosa, which can cause skin rashes and ear infections.